Yellow azo dyestuff



Patented Sept. 14, 1937 UNITED STATES PATENT OFFICE YELLOW AZO DYES'ITUFF Bernard Herstein, Brooklyn, N. Y., assignor to U. S. Industrial Alcohol 00., New York,'N. Y.,' a corporation of West Virginia N Drawing.

Application November 18, 1935,

Serial No. 50,367. Renewed May 17, 1937 1 Claim.

In my copending application, Serial No. 46,123, filed October 22, 1935, I have described and claimed a convenient and economic method for producing ortho nitro para tertiary butyl aniline. This product lends itself very readily to the preparation of an azo dyestuff of the so-called Hansa Yellow group of the following formula:

coupled in the cold with one mol. of acetoace-' tanilid dissolved in an equivalent of sodium hydroxid of sufficient concentration. As is usual in reactions of this character sodium acetate is added while coupling in order to soften or eliminate the efiect of the mineral acid used in diazotization. 6 V

The yellow dyestuff thus obtained after filtere ing, washing and drying has a melting point of about 180 C., is insoluble in water, markedly soluble in alcohol, and appreciably soluble in oil, for instance vegetable oil. 10

I claim:

The herein described yellow dyestufi of the formula:

mom 7 having a melting point of about 180 0., possessing great fastness to light, and being insoluble in water, markedly soluble in alcohol and appreciably soluble in oil.

BERNARD HERSTEIN. 

